We got ethical stem cells.  Or at least we might.  According to New Scientist,

In the plant kingdom ... drastic environmental stress can change an ordinary cell into an immature one from which a whole new plant can arise. For example, the presence of a specific hormone has been shown to transform a single adult carrot cell into a new plant. Some adult cells in reptiles and birds are also known to have the ability to do this.

Researchers in Japan wondered if the same thing would happen with mammals, so they tried it with mice.  These mice had been specially bred to carry a gene that glows in the presence of pluripotent cells -- the cells which can develop into all different types of other cells.  Researchers extracted white blood cells from these specialized mice and subjected the cells to the stress of a weak acid bath for thirty minutes.  Then they waited.

On the second day, the cells started to glow -- signalling that they were producing the protein that only pluripotent stem cells have. When scientists injected these cells with "stimulus-triggered acquisition of pluripotency" (STAP) into mouse embryos, the embryos developed into normal mice -- which, according to New Scientist, not only

incorporated STAP cells into every tissue in their body [but] subsequently gave birth to offspring that also contained STAP cells – showing that the cells incorporated themselves into the animal's sperm or eggs, and were inherited.

Scientists speculate that they are witnessing "Mother nature's repair process" which occurs all over the body when cells are injured.  If the process can be duplicated using human cells, doctors could use them to design relatively cheap and fast cures for macular degeneration and even cancer, tailor made for individual patients from their own white blood cells.  A diseased organ could be "seeded" with injections of healthy cells, which would go to work almost immediately, unlike current  "cell reprogramming therapies," which are expensive and laborious.

Researchers are working on applying their research to human patients, and are speculating that this breakthrough could mean huge advances for patients suffering from serious diseases.  According to the BBC,

Chris Mason, professor of regenerative medicine at University College London, said if [STAP cell therapy] also works in humans then "the age of personalised medicine would have finally arrived."

"If this works in people as well as it does in mice, it looks faster, cheaper and possibly safer than other cell reprogramming technologies - personalised reprogrammed cell therapies may now be viable."

For age-related macular degeneration, which causes sight loss, it takes 10 months to go from a patient's skin sample to a therapy that could be injected into their eye -and at huge cost.

Prof Mason said weeks could be knocked off that time which would save money, as would cheaper components.

As with so many recent advances in the field of biomedical research, there is the potential for ethical horrors as well as miraculous cures.  According to New Science, researchers have discovered that, when STAP cells are modified, they become totipotent, which means even more flexible than pluripotent:  they can, in theory, be turned into a perfect clone.  One scientist claims that he has already made a mouse clone -- not by using transplanted DNA from another animal, as with Dolly the sheep, but with the DNA of only one animal developing into a second, genetically identical animal. Fifteen states in the U.S. have laws governing artificial human cloning; and the Catholic Church deems artificial human cloning as inconsistent with the preservation of human dignity.

No one has used this new technology on humans yet, either to attempt a cure or to grow a clone.  A paper on the new discovery by Japanese researchers has been published in the journal Nature.